It is not about a connection to the EARTH. It is not about a second
floor shack. It has nothing to do with circuit breakers. It IS simply
that every cable shield MUST go to DIRECTLY TO THE CHASSIS.
All that other stuff is bogus ham lore and wandering in the dark.
73, Jim K9YC
On 5/14/2014 2:56 PM, Stuart Rohre wrote:
Some Yaecomwoods do suffer from RF entering the rig.
MOST ANY rig will if you have a bad shield connection on coax jumper,
or have rig too close to the antenna, (second floor shack), and there
are many other rig and feedline issues to rule out in any RFI case.
Rule of thumb: Power all equipment from same circuit breaker of the
house. That ensures AC grounds will not be coming from widely
different locations. IF you have to use a long ground wire for
lightning protection ground on the station (like from second floor
shack), consider that it could act as an "antenna" for pick up of RF
from the real antenna. You may need tuned radials, or a radial for
each favorite band.
You could always examine the quality of the grounding of the mike
cable shield. Some older mike cords had just a multi-strand wire
wrapped in one direction and not a hatch pattern wire shield. Some
aluminum foil shields don't make a good low impedance connection by
clamping. (Connections that can't be soldered are suspect).
You can do a step by step analysis of grounding, by starting at the
mike element and measure the resistance by ohm meter, of shield
connection to plug pin/ shell. Use a magnifier to examine connections
on inside of radio at mike. Check case to mike jack shell if that type.
Some radios have a thru bolt to provide a "ground" terminal on back of
set. Make sure this bolt if present, grounds tightly to the chassis.
Same could be said for any stud grounds on external tuner, etc.
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